Note that, for the
following paragraph, later versions of Windows, including Windows 7,
don't require the Settings step and Regional Settings is
now Region and Language.

Click on Start, then Settings, then Control Panel. On
the Control Panel, double click on the Regional Settings
icon. The dialog box shown here will appear (although the Regional
Settings tab will initially be selected). Follow the instructions in
the illustration, then scroll down to the second illustration and follow
the instructions there to set the time format.

The differences
between the Regional Settings panel shown below and that of Windows Me and
Windows 2000 are minor or non-existent. For Windows XP, there is some
rearrangement, but the options are easy to find. For Windows 7, which has
made the entire process much simpler, scroll to the bottom of the page.

Note that, for the
long date style, the year-month-day sequence (and its punctuation) is
simply a recommendation. ISO 8601 does not deal with long dates (where the
month is spelled out).

Close this window
when you've finished with it. The SI Navigator window will
still be open.